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Lunar south pole region
A mosaic of the Moon's south polar region created from images from ESA’s SMART-1 orbiter. Isolated peaks at the Moon’s poles could receive sunlight nearly all of the time, making them valuable sites for lunar bases. (credit: ESA)

A legal regime for lunar peaks of eternal light

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Astronomers define “peak of eternal light” (PEL) as a point on a celestial body that always receives sunlight. Recent evidence has confirmed the existence of such points in the polar regions of the Earth’s Moon. Peaks of eternal light are of immense importance to the establishment of permanent human communities or robotic industries on the Moon because they allow for steady and reliable energy from constant solar radiation throughout the lunar day. The significance of such regions on the lunar surface for future habitats or settlements is so high that studying the legal regime of peaks of eternal light is a prerequisite for any actual development on the lunar surface. This article tackles the actual legal regime of PELs on the Moon and reviews alternative legal implications as to the usage of this precious extraterrestrial real estate.


The existence of such peaks was first postulated by Beer and Mädler in 1837 saying with respect to the lunar polar mountains, “...Many of these peaks have (with the exception of eclipses caused by the Earth) eternal sunshine.”1 In some locations, there are “peaks of eternal light,” or pics de lumière éternelle, as the French astronomer Camille Flammarion called them at the end of the nineteenth century.2 NASA’s Clementine spacecraft orbited the Moon for three months in 1994. It identified some spots in the north polar region that are illuminated all the time during the summer, and others that are illuminated 80 percent of the time.

This was not a big surprise, because we know that on Earth the poles receive a lot of sunlight during the summer. A question that the European Space Agency wanted to answer with the SMART-1 mission was whether there is enough solar light to still illuminate these places in winter.

SMART-1 mapped the polar areas on the Moon, and astronomers recently found an illuminated site about 15 kilometers from the North Pole. Even though most of the moon is dark in that region, there is a crater wall tall enough for sunlight to strike its rim.

Such perpetually lit areas would be good places to start our exploration of the Moon.

The lunar South Pole is situated in a huge depression, leading to 16-kilometer altitude differences over the region. Careful analysis of imagery and topographic conditions on the lunar South Pole by teams from NASA and Europe revealed a small number of illuminated ridges within 15 kilometers from the pole, each of them much like an island no more than a few hundred meters across in an ocean of eternal darkness, where a lander could receive near-permanent lighting (about 70–90% of time in lunar winter, and likely 100% in lunar summer.)3

Such perpetually lit areas would be good places to start our exploration of the Moon. If you didn’t want to rely on complex power systems, you could install solar power stations at the peaks and use the energy to run small rovers and landers. Such systems are easier to design than electrical and mechanical systems that must withstand the extreme variations of temperature between lunar day and night. Branching out from there, you could build a spider web of facilities and habitats, with the core feeding energy to surrounding areas.4

Who can own peaks of eternal light on the Moon?

Space law is the major body of international law that addresses the regulatory framework with which countries in their space activities should comply. Among five distinct treaties and agreements comprising the space law, the Treaty Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies, is of immense importance specifically with regard to the general outlines that plans to explore and use the peaks of eternal light on the Moon have to comply with.

According to Article II of Outer Space Treaty of 1967, no country can claim national sovereignty over the peaks of eternal light on the moon. Article II states, “Outer space, including the Moon and other celestial bodies, is not subject to national appropriation by claim of sovereignty, by means of use or occupation, or by any other means.”

That is to say installation of equipment or even establishment of a station on or near the PELs won’t provide any legal basis for nations to claim the extension of their national sovereignty beyond the Earth. The positive point within this article is that the nations who have signed or ratified the Outer Space Treaty have agreed not to limit the free access to celestial bodies for conducting scientific research, or any other peaceful activities pursued by other nations party to the Treaty. This issue has been well addressed in Article I and IX of the Treaty. The former holds that the Moon and other celestial bodies shall be free for exploration and use by all states without discrimination of any kind, on a basis of equality and in accordance with international law, and there shall be free access to all areas of celestial bodies. In the meantime, the later insists on the spirit of cooperation and mutual assistance between the nations in their endeavors for exploration and use of outer space, including the Moon and other celestial bodies.

So far, although countries cannot claim the ownership the PELs, still they are free to explore and use those precious areas on the Moon’s polar regions. However, we should take into consideration the fact that peaks of eternal light on lunar poles are actually just summits of the lunar mountains and are not large enough to place numerous installations of many countries. Accordingly there might be shortage of real estate on the Moon in terms of PELs.

However, as to use of peaks of eternal lights on the Moon’s poles, the principle of “first come, first serve” would be applicable.

Article IX of the Treaty urges the parties to the Treaty to uphold the principle of cooperation and mutual assistance in their exploration and use of outer space, including the Moon and other celestial bodies. Also, member states ought to consider the corresponding interests of all other parties to the Treaty. In other words and relying on the content of Outer Space Treaty, no state is allowed to monopolize the usage of peaks of eternal light on the Moon’s polar regions. Since the main use of PELs would be providing electricity through installed solar panels, the Treaty could be interpreted to mean that either other countries may install their own solar panels as well, or they can take advantage of emplaced installation and use the produced electricity. The question that here may arise is that what would happen if the principle of cooperation and assistance couldn’t be upheld and two states cannot compromise on mutual use of PELs?

Who can use PELs?

Article I of the Treaty calls upon the member countries to consider the interest and benefit of all countries in their efforts for exploring and using outer space, including the Moon and other celestial bodies. Also, outer space is regarded as the province of all humanity, which means all countries irrespective of their degree of economic or scientific development have undeniable equal right to enjoy free access to explore and use space, including the Moon and other planets or asteroids. Furthermore, the freedom of exploration and use by all nations without discrimination is explicitly recognized.

However, as to use of peaks of eternal lights on the Moon’s poles, the principle of “first come, first serve” would be applicable: that is, countries that allocate enough resources and finance in exploring and using the PELs before the others would benefit a privileged position in the most precious lunar real estate in the years to come. Moreover, once a country successfully establishes its installations or devices on the PELs, any consequent newcomer who aims at using the same PEL has to take notice of the priority of installations already using the location. Thus, the secondary country may not affect or damage the proper function of the first country’s installed devices or machineries by those of its own. If such circumstances happen, then the affected country may seek to convince the intruder to revise his conduct.

Conflict of interests on PELs

It is interesting to note that the Outer Space Treaty lacks any provisions that would regulate the methods of the settlement of eventual disputes, which usually appear in lawmaking treaties like the 1959 Antarctic Treaty. The reason for this omission is the difference of opinion that existed between the two major space powers and their supporters on introducing compulsory or only facultative dispute settlement methods. Little effort was devoted to resolving this widely-known issue and the consultations provided for in Article IX became the only applicable method to prevent or remove any problems in the mutual relations between the States parties to the Treaty.5 The Outer Space Treaty acknowledges the non-interference principle in terms of peaceful space activities. In other words, states are not allowed to interrupt the function of other states’ facilities by their own activities whatsoever. This notion is crystalized in article IX of the Treaty as it reads:

“A state Party to the Treaty which has reason to believe that an activity or experiment planned by another State Party in outer space, including the Moon and other celestial bodies, would cause potentially harmful interference with activities in the peaceful exploration and use of outer space, including the Moon and other celestial bodies, may request consultation concerning the activity or experiment.”

The consultancy entity that the Treaty refers to is more likely the United Nations Committee on the Peaceful Uses of Outer Space, or COPUOS. This Committee on the Peaceful Uses of Outer Space was set up by the General Assembly in 1959 (resolution 1472 (XIV)) to review the scope of international cooperation in peaceful uses of outer space. The main tasks of COPUOS are to devise programs in this field to be undertaken under United Nations auspices, to encourage continued research and the dissemination of information on outer space matters, and to study legal problems arising from the exploration of outer space. For the time being, 74 countries are member states in COPUOS.

COPUOS has two standing subcommittees of the whole: the Scientific and Technical Subcommittee; and the Legal Subcommittee. The committee and its two subcommittees meet annually to consider questions put before them by the General Assembly or reports submitted to them and issues raised by the member states. COPUOS and its subcommittees, working on the basis of consensus, make recommendations to the General Assembly. Detailed information on the work of the committee and the subcommittees are contained in their annual reports. COPUOS is very active: its 56th session took place June 12–21, 2013, at the United Nations Office at Vienna, Austria.

Depending on the nature of the dispute raised out of use of PELs on the Moon, the matter could be brought before scientific or legal subcommittee of the COPUOS, who, after scrutinizing the issue, will render adequate consultancies for involved states or General Assembly if applicable. It is noteworthy that expert opinions of COPUOS are not obligatory and in case the states in the dispute refuse to enforce the issued consultancies, there is no other way to make them alter their plans or conduct regarding use of PELs but to refer the matter to the Security Council of the United Nations.

Bringing a matter in terms of using the PELs on the Moon before Security Council requires the same procedure as all other situations that threaten international peace and security, stipulated in the Charter of United Nations. However, involvement of Security Council in conflict of interests on the Moon will remain the last resort and final option for spacefaring countries that encounter the most severe unsolved problems with other spacefarers on the Moon. This notion is implied in the wording of the Article III of the Treaty:

“States Parties to the Treaty shall carry on activities in the exploration and use of outer space, including the Moon and other celestial bodies, in accordance with international law, including the Charter of the United Nations, in the interest of maintaining international peace and security and promoting international co-operation and understanding.”

Private sector activities on PELs

In the last decade, we has seen the creation of private companies that target outer space as their field of economic activities. Telecommunications, space tourism, and mining and extracting the extraterrestrial resources from near Earth asteroids are among the fields that private companies either are currently active in or plan to get involved in future. It is very likely that private companies will become the first pioneers of using the PLEs on the Moon, which would be a strong step forward for the establishment of a privately owned extraterrestrial commerce network beyond planet Earth.

Sooner or later the world will witness a huge rush to explore, mine, and use lunar resources, creating opportunities for sophisticated interaction or even conflict of laws on the lunar surface.

Such situation may seem complicated, but the Outer Space Treaty put forward legal basis for private sector involvement in exploration and exploitation of outer space decades ago. Article VI of the Treaty tackles the non-governmental activities in outer space, stating that the parties to the Treaty shall bear international responsibility for their nationals, either legal or natural, that are active in space in one way or another. Accordingly, nations have to regulate the framework of private companies’ activities on the PELs, such that if any misconduct or damage to other’s properties is caused, then the government is responsible to remedy the damages or losses not the private companies. This will signify the supervisory role of governments over private endeavors on the Moon. Such governmental supervision is attained via various methods including but not limited to:

  • Licensing companies that are eligible to perform such activities by their respective nation;
  • Establishment of state controlled associations of private companies;
  • Setting up consortia of public and private companies; and
  • Establishment of an international organization to regulate private activities in the Moon through licensing and supervising the observance of Outer Space Treaty principles on the Moon and elsewhere in space.

Among those solutions, establishment of an international organization for regulating the use of PELs seems to be the most viable and practical, as examined below.

Proposal for an international organization for using the PELs

As the time passes on, the importance of the Moon for the future of space exploration and exploitation becomes increasingly clear. As a matter of fact, the potential for lucrative lunar activities is not limited to peaks of eternal lights and likelihood of providing reliable source of energy. Presence of vast amounts of helium-3 isotope deposits within lunar soil6 together with newly discovered water ice accumulated in permanently-shadowed regions of impact craters7 should be added to prospective fields of interest for extraterrestrial commercial activities in one way or another.

Such potential resources may attract not only the governmental agencies of spacefaring nations, but private companies as well. Sooner or later the world will witness a huge rush to explore, mine, and use lunar resources, creating opportunities for sophisticated interaction or even conflict of laws on the lunar surface. This assumption could be valid anywhere else where numerous space activities of commercial nature are conducted. Accordingly, referring the activities on the Moon to the general principles of Outer Space Treaty and national regulations of spacefarers may be problematic because the former has solely outlined common general issues and the later only deals with one-sided interests and objectives. Hence, for tuning the space activities on the Moon in a constructive way, by which collective interests as well as specific characteristics of PELs are considered, a new set of legal approaches is required.

Based on these, one of the best solutions for regulating the use of PELs on the Moon might be through establishment of an international organization that on one hand safeguards observance of Outer Space Treaty principles and, on the other hand, sets forth practical mandates for exploring and using PELs.

It is crucial for space law to expand the principles set forth in Outer Space Treaty to the actual realm of space commercialization so that economic incentives can play their historic role in fueling exploration of new frontiers and consequently expand human civilization beyond its home planet, the Earth.

Establishment might be realized via adoption of an international treaty or expansion of bilateral agreements to third parties who are interested in the use of PELs on the Moon. Such an organization, once established, shall have two main functions: provision of sectorial rules and dispute settlement. A good instance for such specific functions assigned to an organization might be the International Maritime Organization, who enforces both above-mentioned functions in terms of maritime transport, security of use, and environmental issues. The realization of an organization for regulating commercial and legal issues of space users first and foremost depends on political desires of spacefarer nations. In fact, without the collective consensus of space powers, establishment of an entity for use of PELs will not materialize. Greater awareness of the needs of space industries, and the potential for legal problems such activities could create, is important now before those problem occur. Trial and error has proved to be very costly with regard to international commerce and business, so space law ought to provide in advance functional codes of conduct to tackle the inevitable commercialization of outer space in general and peaks of eternal light on the Moon in particular.


All attempts to address the legal regime of PELs and specified criteria and solutions could be applicable to other commercial activites of the Moon including but not limited to water, minerals, and even special orbits. This may ease the task assigned to space lawyers because once one of these issues is resolved, the legal findings can be applied to other fields and subjects because they all are correlated within the body of present space law. It is worth noting that legal regime of lunar PELs and other resources and opportunities apply to other celestial bodies quite well. It is crucial for space law to expand the principles set forth in Outer Space Treaty to the actual realm of space commercialization so that economic incentives can play their historic role in fueling exploration of new frontiers and consequently expand human civilization beyond its home planet, the Earth.


1 Beer, Wilhelm, Mädler, Johann Heinrich. Der Mond nach seinen kosmischen und individuellen Verhältissen oder allgemeine vergleichende Selenographie. Berlin, Simon Schropp and Co., 1837.

2 Flammarion, Camille. Astronomie Populaire, description générale du ciel. Paris, 1879.

3 Kruijff, M., The Peaks of Eternal Light on the Lunar South Pole: How they were found and what they look like, 4th International Conference on Exploration and Utilization of the Moon (ICEUM4), ESA/ESTEC, SP-462, September 2000.

4 Bernard Foing, Peaks Of Eternal Light Point To Lunar Ice Sites, last visited at 10/19/2013

5 Vladimír Kopal, introductory notes on Outer Space Treaty, Last visited at: 10/23/2013

6 Johnson, Jeffrey R.; Swindle, Timothy D.; Lucey, Paul G. (1999). "Estimated Solar Wind-Implanted Helium-3 Distribution on the Moon". Geophysical Research Letters ( 26 (3): 385. Bibcode:1999GeoRL..26..385J

7 ScienceDaily. Retrieved November 3, 2013, from